Roll forming machine drive mechanism

ABSTRACT

A roll forming machine having a crank assembly with a crank wheel and a crank pin support plate mounted on an integral eccentric of the crank wheel for securely positioning the crank pin at each of a plurality of angularly spaced positions about the axis of the crank wheel and having different crank pin eccentricities for establishing different strokes of a reciprocable roll forming die of the machine.

States Patent [191 Crohoski [111 3,839,891 [451 Oct. 8, 1974 1 ROLL FORMING MACHINE DRIVE MECHANISM [75] Inventor: Edward G. Grohoski, Litchfield,

Conn.

[73] Assignee: The Hartford Special Machinery Company, Simsbury, Conn.

[22] Filed: Mar. 26, 1973 [21] Appl. No.: 344,490

[52] 11.5. C1. 72/88 [51] Int. Cl. B21h 3/06 [58] Field of Search 72/88, 90; 74/571 M, 600

[56] References Cited UNITED STATES PATENTS 1,108,425 8/1914 Brennan ..72/9() 2,477.58? 8/1949 Doutt ..74/551M 3,117,473 1/1964 Morton et a1 t. 72/90 3,308,642 3/1967 Morton 72/88 3,626,768 12/1971 Duncsik 74/600 Primary Examiner-Milton S. Mehr Attorney, Agent, or Firm-Prutzman, Hayes, Kalb & Chilton [5 7 ABSTRACT A roll forming machine having a crank assembly with a crank wheel and a crank pin support plate mounted on an integral eccentric of the crank wheel for securelypositioning the crank pin at each of a plurality of angularly spaced positions about the axis of the crank wheel and having different crank pin eccentricities for establishing different strokes of a reciprocable roll forming die of the machine.

7 Claims, 2 Drawing Figures I ROLL FORMING MACI-IINE DRIVE MECHANISM BRIEF SUMMARY OF THE INVENTION This invention relates generally to roll forming machines of the type disclosed in U.S. Pat. No. 3,308,642 of Robert D. Morton entitled Thread Rolling Machine and useful for example for rolling threads on suitable blanks for forming threaded fasteners or the like and conventionally having a die assembly with replaceable stationary and reciprocable flat dies for roll forming the blanks and a feed mechanism for timely feeding the blanks to the die assembly.'More particularly, the present invention relates to a new and improved drive mechanism for the reciprocable die of a roll forming machine which is adjustable for adjusting the stroke of the reciprocable die.

It is a primary aim of the present invention to provide a new and improved roll forming machine drive mechanism which permits ready adjustment of the stroke of the reciprocable die of the roll forming machine in accordance with the size of the die employed and/or the size of the part to be formed.

It is another aim of the present invention to provide in a roll forming machine drive mechanism of the type having a driving crank wheel with an eccentric crank pin and a connecting rod interconnecting the crank pin and the reciprocable die of the roll forming machine, a new and improved crank wheel assembly providing adjustment of the eccentricity of the crank pin for adjusting the stroke of the reciprocable die.

It is a further aim of the present invention to provide a new and improved crank wheel assembly for a roll forming machine which permits adjustment of the eccentricity of the crank pin without disassembling the connecting rod from the crank pin.

Other objects will be in part obvious and in part pointed out more in detail hereinafter.

A better understanding of the invention will be obtained from the following detailed description and the accompanying drawings of an illustrative application of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. I is a top plan view, partly broken away, of a roll forming machine incorporating-an embodiment of the present invention; and

FIG. 2 is an enlarged elevation section view, partly broken away and partly in section, taken substantially along line 22 of FIG. 1, showing a crank wheel assembly of the roll forming machine.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings in detail, there is illustrated in FIG. 1 a roll forming machine of the type shown and described in the aforementioned U.S. Pat. No. 3,308,642. The machine generally comprises an elongated table 12, a guide track 14 adapted for conveying suitable blanks (not shown) in line from a hopper (not shown) to adjacent a pair of cooperating stationary and reciprocable flat dies 16, 18 respectively. In the machine shown, the stationary die 16 is detachably mounted on a stationary die block 19 by an adjustable clamp 20 and the reciprocable die 18 is mounted on a slide 22 by a similar adjustable clamp 24. In a conventional manner, the slide 22 is mounted for rectilinear reciprocable movement on a slide support block 26 which can be laterally adjusted on the table I2 by a pair of adjusting screws 30 for setting the alignment and spacing of the stationary and reciprocable dies I6. 18.

The guide track 14 is preferably inclined so that the blanks are gravity fed between the rails 34 of the track to the lower end of the track adjacent the reciprocable die 18. A combination gate and starter finger 36 is mounted adjacent the lower end of the track M- for reciprocable movement generally parallel to and between the stationary and reciprocable dies I6, 18 and is connected to be driven for feeding blanks in sequence one at a time from the track 114 to an initial position shown in FIG. 1 between the leading edges of the dies 16, I8 and such that the blank is fed in timely cooperation with the reciprocable movement of the slide 22.

A mechanism for driving the slide 22 includes a crank wheel assembly 40 driven by a suitable speed reducer (not shown) which is manually controllable by a handle 43 for varying the rotational speed of the crank wheel assembly 40. The crank wheel assembly 40 is supported on the table 12 by suitable bearings (not shown) for rotation about an axis which extends substantially perpendicular to the axis of reciprocable movement of the slide 22.

The combined gate and starter finger 36 is operated by an annular cam 44 which forms a part of the crank wheel assembly 40. A bell crank 50 having a cam follower 51 engageable with the circumferential edge of the cam 44 provides for timely operating the combined gate and starter finger 36 through an adjustable variable length connecting rod 53 and a pivotal arm 54 which supports the combined gate and starter finger 36.

The crank wheel assembly 40 is connected by a connecting rod or pitman arm 56 for reciprocating the slide 22 and therefore the driven die 18. One end of the connecting rod 56 is rotatably mounted on a crank pin 57 of the crank wheel assembly 40 and the other end of the connecting rod is pivotally connected to the slide through a pivot pin 58. Accordingly, for each revolution of the crank wheel assembly 46 the reciprocable die I8 is reciprocated through one complete cycle and the stroke of the die 18 is dependent upon the eccentricity of the .crank pin 57. The combined gate and starter finger 36 of the blank feed mechanism is also reciprocated through' one complete cycle by the cam 44 during each revolution of the crank wheel assembly 4(L Referring to FIG. 2, the crank wheel assembly 40 stantially vertical rotational axis 61 and integrally formed with a central upstanding cylindrical support 62 having its geometric axis 65 parallel to and slightly offset from the rotational axis 61 of the crank wheel 60. The crank wheel is also formed with a peripheral annulus 66 having a first coaxial annulus portion 67 for receiving the cam 44 and permitting coaxial angular adjustment of the cam 44 on the crank wheel 60 to accurately time the operation of the blank feed mechanism. A second eccentric annulus portion 70 of the annulus 66 is provided at the upper edge of the crank wheel 60 for receiving an annular clamping plate 72;. The annulusportion 70 is formed. concentrically with the geometric axis of the eccentrically formed support 62 and the clamping plate 72 is dimensioned to overlie and engage the inner portion of the cam 44 and is keyed against angular displacement on the crank wheel by a locating pin 74.

A crank pin subassembly is mounted on the upper face 81 of the crank wheel 60 such that its crank pin 57 may be angularly shifted around the crank wheel 60 to adjust the eccentricity of the crank pin 57. The

Y crank pin subassembly 80 comprises a generally flat annular mounting plate 82 integrally formed with the upstanding crank pin 57 and having a coaxial circular opening for receiving a suitable bushing 86 for supporting thecrankpin subassembly for angular adjustment around the eccentric support 62. Eight hexagonal socket head cap screws 88', 89 equiangularly spaced around a circle coaxial with the eccentric axis 65 of the upstanding support 62 are employed for firmly securing the plate 82 to the upper face 81 of the crank wheel 60, The crank wheel 60 similarly comprises eight cooperating equiangularly spaced threaded openings 90 such 20 that the plate 82 may be selectively secured in each of eight equiangularly spaced positions about the eccentric axis 65 and therefore in eight substantially equiangularly spaced positions about the crank wheel axis 61. As can be seen from the drawings, the socket head fastener 89 is elongated and is mounted to extend coaxially through the upstanding crank pin 57 to assist in rigidly securing the crank pin 57 to the crank wheel 60.

In the shown embodiment, the connecting rod 56 is rotatably mounted on the crank pin 57 with a roller bearing 92. An inner race 93 of the roller bearing 92 is secured onto the crank pin 57 against a lower locating shoulder 94 of the crank pin 57 by a suitable lock nut 95 threaded onto a reduced threaded portion 96 of the crank pin 57. An outer race 98 of the roller bearing 92 is mounted within an intermediate eccentric bushing 100 of the connecting rod 56 in engagement with an inner locating shoulder 102 of the bushing 100 and is held in place by an annular cap 104 secured by fasteners 106 to the end of the bushing 100 and an annular spacer 108. A suitable upper seal 110 is mounted between the cap 104 and upper reduced cylindrical end 111 of the upstanding crank pin 57 and a suitable grease fitting 112 is mounted on the cap 104 for lubricating the bearing 92. Also, a suitable lower seal 114 is shown mounted between the eccentric bushing 100 and a lower enlarged end 115 of the crank pin 57.

The bushing 100 is secured in a conventional manner within the bearing socket 116 of the connecting rod 56 by a suitable hexagonal socket head cap screw 118 extending between the bifurcated end portions 119, 120 of the bearing socket 116. Additionally, three equiangularly spaced plates 122 mounted within a peripheral annulus 124 in the bushing 110 and adjustably secured to the bearing socket 116 by cap screws 126 are provided for properly axially locating the connecting rod bearing socket 116 on the crank pin 57 so that the connecting rod 56 extends normal to the axis of the crank pm.

It can be seen that by merely removing the cap screws 88, 89 and rotating the crank pin support plate 82 about the eccentric support 62, the crank pin 57 can be selectively located in each of eight substantially equiangularly spaced positions about the axis of the crank wheel 60. In the shown embodiment, the axes 120, 121 of two of the threaded openings 90 in the crank wheel 60 lie on a common plane with the axis 61 of the crank wheel 60 and the axis 65 of the eccentric support 62. Accordingly, a minimum available crank pin eccentricity and therefore a minimum die stroke is obtained by locating the crank pin 57 coaxially with the axis 121, and a maximum available crank pin eccentricity and therefore a maximum die stroke is obtained by locating the crank pin 57 coaxially with the axis 120, and the available eccentricity or stroke variation is equal to twice the distance between the axes 61, 65. Intermediate angular positions of the crank pin 57 provide for intermediate crank pin eccentricities or die strokes and of course any desired number of such intermediate positions can be obtained by providing suitable additional threaded apertures 90 in the crank wheel 60. To facilitate locating the crank pin for providing the desired die stroke, a reference plate 126 may be secured to the upper face of the eccentric support 62 to show the die stroke at each crank pin position.

The crank pin subassembly 80 is preferably suitably dynamically balanced about the eccentric axis 65 such that the dynamic unbalance caused by the crank pin subassembly 80 remains the same and relatively small at each of the available positions of the crank pin 57.

The dynamicunbalance caused by the crank pin subassembly can then be completely offset by properly dynamically counterbalancing the remainder of the crank wheel subassembly 40. Also, the cam 44 is preferably dynamically balanced so that angular adjustment of the cam 44 in accordance with the angular position of the crank pin subassembly 80 will not effect the dynamic balance of the entire crank wheel assembly 40. For simplifying the required angular readjustment of the cam 44 when the crank pin 57 is repositioned, appropriate alignment marks 130, 131 may be provided on the crank pin support plate 82 and cam 44 for properly angularly positioning the cam 44 relative to the crank pin 57. Also, a suitable number of angularly spaced set screws 134 are mounted on the crank pin support plate 82 for engagement with the clamping ring 72 for clamping the ring against the cam 44 for thereby locking the cam 44 against rotation. Thus, when the cap screws 88, 89 are removed to reposition the crank pin 57, the cam 44 is also thereby unclamped to permit the cam 44 to be properly repositioned before the cap screws 88, 89 are tightened to simultaneously secure the crank pin 57 and cam 44 against rotation.

Where necessary, after replacement of the stationary and reciprocable dies 16, 18 respectively, or after adjustment of the stroke of the reciprocable die, the stationary and reciprocable dies may be matched for properly aligning their opposed die surfaces by adjusting the effective length of the connecting rod 56. This is accomplished in a convenient manner by angular adjustment of the eccentric bushing 100 within the bearing socket 1 16 of the connecting rod, which adjustment is readily accomplished by loosening the fastener 118 and revolving the bushing cap 104, for which purpose the cap 104 is provided with a gear sector 136 and the connecting rod is provided with an opening 138 for a conventional gear key or wrench (not shown).

It can be seen that the roll forming machine of the present invention incorporates an advantageous and useful drive mechanism for the reciprocable die which permits ready adjustment of the stroke of the die and for mating the faces of the stationary and reciprocable dies. Such adjustments are particularly useful where it is desirable to use a die or perform a roll forming operation which requires a die stroke less than the maximum stroke of the machine. Accordingly, the dies 16, 18 can be, for example, substantially smaller than the maximum size for which the machine is designed for which purpose adaptors 146, 148 are used for mounting the stationary and reciprocable dies, respectively. The

ous modifications and adaptations of the structure above described will become readily apparent without departure from the spirit and scope of the invention, the scope of which is defined in the appended claims.

I claim:

ll. In a roll forming machine having a die assembly with a reciprocable die and a die drive mechanism with a drive crank wheel assembly with an eccentric crank pin and adjustable to establish the eccentricity of the crank pin and a connecting rod having' one end mounted on the crank pin and its other end connected to the reciprocable die to establish a die stroke in accordance with the crank pin eccentricity, the improvement wherein the crank wheel assembly comprises a rotatable crank wheel having an axially facing support face, a crank member having a generally circular crank support plate mounted on the crank wheel support face generally coaxially therewith for angular adjustment about an axis laterally offset from the crank wheel axis and an integral axially extending crank pin, the generally circular crank support plate having its axis of angular adjustment relatively slightly laterally offset from the axis of the crank wheel and relatively substantially laterally offset from the axis of the crank pin, and a plurality of releaseable fastenermeans angularly spaced about the axis of the crank wheel for selectively securing the circular crank support plate to the crank wheel support face in each of a plurality of angularly spaced sible to selectively secure the crank support plate in each of said angularly spaced positions with the connecting rod mounted on the crank pin.

2. In a roll forming machine according to claim I wherein the crank wheel and crank support plate comprise eccentric mounting means for mounting the crank support plate for angular adjustment on the crank wheel about said offset axis of the crank support plate.

3. In a roll forming machine according to claim 2 wherein the eccentric mounting means comprises an integral eccentric of the crank wheel extending axially outwardly from the crank wheel support face and bearing means of the crank support plate'for mounting the crank support plate on the eccentric for said angular adjustment.

4. A roll forming machine according to claim 1 v wherein the plurality of releaseable fastener' means comprise a plurality of separate fasteners equiangularly spaced about a circle having its center on the offset axis of the crank support plate.

5. A roll forming machine according to claim I wherein the machine comprises a feed mechanism operable for feeding blanks to the die assembly for being roll formed, and wherein the crank wheel assembly comprises an annular cam mounted on the crank wheel for operating the feed mechanism and angularly adjustable .about the axis of the crank wheel for timely feeding a blank to the die assembly, the annular cam being mounted on the crank wheel axially inwardly of the crank support plate, and releaseable clamping means including means on the crank support plate for clamping the annular cam against rotation on the crank wheel and automatically released when the fastener means are released to secure the crank support plate at a different position on the crank wheel support face.

6. A roll forming machine according to claim 5 wherein said means on the crank support plate comprises a plurality of clamping screws adjustably threaded into the crank support plate for clamping the annular cam against rotation on the crank wheel when the crank support plate is secured to the crank wheel support face.

7. A roll forming machine according to claim 5 wherein the releaseable clamping means comprises a clamping ring mounted in the crank wheel intermediate the annular cam and crank support plate for clamping the annular cam against rotation on the crank wheel when the crank support plate is secured to the crank wheel support face. I 

1. In a roll forming machine having a die assembly with a reciprocable die and a die drive mechanism with a drive crank wheel assembly with an eccentric crank pin and adjustable to establish the eccentricity of the crank pin and a connecting rod having one end mounted on the crank pin and its other end connected to the reciprocable die to establish a die stroke in accordance with the crank pin eccentricity, the improvement wherein the crank wheel assembly comprises a rotatable crank wheel having an axially facing support face, a crank member having a generally circular crank support plate mouNted on the crank wheel support face generally coaxially therewith for angular adjustment about an axis laterally offset from the crank wheel axis and an integral axially extending crank pin, the generally circular crank support plate having its axis of angular adjustment relatively slightly laterally offset from the axis of the crank wheel and relatively substantially laterally offset from the axis of the crank pin, and a plurality of releaseable fastener means angularly spaced about the axis of the crank wheel for selectively securing the circular crank support plate to the crank wheel support face in each of a plurality of angularly spaced positions of the crank support plate about its offset axis providing a plurality of different crank pin positions angularly spaced about the axis of the crank wheel and having a plurality of different crank pin eccentricities, the plurality of releaseable fastener means being accessible to selectively secure the crank support plate in each of said angularly spaced positions with the connecting rod mounted on the crank pin.
 2. In a roll forming machine according to claim 1 wherein the crank wheel and crank support plate comprise eccentric mounting means for mounting the crank support plate for angular adjustment on the crank wheel about said offset axis of the crank support plate.
 3. In a roll forming machine according to claim 2 wherein the eccentric mounting means comprises an integral eccentric of the crank wheel extending axially outwardly from the crank wheel support face and bearing means of the crank support plate for mounting the crank support plate on the eccentric for said angular adjustment.
 4. A roll forming machine according to claim 1 wherein the plurality of releaseable fastener means comprise a plurality of separate fasteners equiangularly spaced about a circle having its center on the offset axis of the crank support plate.
 5. A roll forming machine according to claim 1 wherein the machine comprises a feed mechanism operable for feeding blanks to the die assembly for being roll formed, and wherein the crank wheel assembly comprises an annular cam mounted on the crank wheel for operating the feed mechanism and angularly adjustable about the axis of the crank wheel for timely feeding a blank to the die assembly, the annular cam being mounted on the crank wheel axially inwardly of the crank support plate, and releaseable clamping means including means on the crank support plate for clamping the annular cam against rotation on the crank wheel and automatically released when the fastener means are released to secure the crank support plate at a different position on the crank wheel support face.
 6. A roll forming machine according to claim 5 wherein said means on the crank support plate comprises a plurality of clamping screws adjustably threaded into the crank support plate for clamping the annular cam against rotation on the crank wheel when the crank support plate is secured to the crank wheel support face.
 7. A roll forming machine according to claim 5 wherein the releaseable clamping means comprises a clamping ring mounted in the crank wheel intermediate the annular cam and crank support plate for clamping the annular cam against rotation on the crank wheel when the crank support plate is secured to the crank wheel support face. 